Using old dried usnea for tincture?

So I have a bunch of dried usnea that is a few months old and has been stored in a mason jar away from direct sunlight. Can I make a tincture with this or does it have to be fresh? Also does it matter if it’s dried or does it have to be hydrated before tincture?

Personally, I would use it. I'd fill a jar 1/3 full, add 40proof alcohol (vodka, brandy, whiskey, or rum, but not a liquer) almost to the top, and shake it well, daily for 6wks or so. If you need it sooner, you can use one of the heat-tincturing methods.

Edited to correct - 80proof, not 40. I got my proof & abv backwards. This is a good use for high-proof Everclear.

Usnea is a double extraction tincture, i.e. alcohol and water process.  In any case, it would benefit to use a 90 degree proof alcohol .

Dried herbs lose their medicinal value as time goes on, after a year it is worth very little, so if your Usnea is on the wrong side of " a few months", I would get some fresh one, since you can find Usnea more or less all year long.

This, of course, is only my two cents worth!

This might help: https://www.foraged.com/blog/how-to-make-usnea-tincture-a-step-by-step-guide-to-crafting-your-own-herbal

You can definitely use dried usnea to make a tincture. There's no need to use fresh usnea for this—dried works just as well. Just make sure it's stored properly, which it sounds like it is since it's been in a mason jar away from sunlight. For making the tincture, you'll want to chop or crumble the dried usnea a bit to help with the extraction process. Then, place it in a jar and cover it with alcohol, like vodka, at a ratio of about 1 part usnea to 5 parts alcohol. Seal the jar and let it sit in a cool, dark place for at least 4-6 weeks, shaking it gently every few days. After that period, strain out the usnea, and you’ll have a tincture ready to use. The dried usnea will still provide all its beneficial properties, so you're good to go with what you have!

I wouldn't bother with high-proof. The usnea is dry, it will take up water. High-proof is for wet/fresh herbs.
A few months isn't old. Over a year could be old, depending on how it looks and tastes.
You can also use it in soup - cook until disintigrated - if you don't hate the taste.